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Custom constraint for the field's value
Source position: db.pas line 443
published property TField.CustomConstraint : string |
CustomConstraint may contain a constraint that will be enforced when the dataset posts it's data. It should be a SQL-like expression that results in a True or False value. Examples of valid constraints are:
Salary < 10000 YearsEducation < Age
If the constraint is not satisfied when the record is posted, then an exception will be raised with the value of ConstraintErrorMessage as a message.
This feature is not yet implemented in FPC.
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Message to display if the CustomConstraint constraint is violated. |
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Constraint for the field value on the level of the underlying database |